Snubbing apparatus for oil wells



Feb. 20, 1934. L. M. c. SEAMARK SNUBBING APPARATUS FOR OIL WELLS Filed NOV. 27, 1931 5 Sheets-Sheet l Inventor Jug] fiazmaz/r by 2W.

Feb. 20, 1934- M. c SEAMARK SNUBBING APPARATUS FOR OIL WELLS Filed NOV. 27, 1931 5 Sheets-Sheet 2 Feb. 20, 1934. 1.. M. c. SEAMARK SNUBBING APPARATUS FOR OIL WELLS Filed Nov. 27, 1931 5 Sheets-Sheet 5 Feb. 20, 1934. 1. M. c. SEAMARK SNUBBING APPARATUS FOR OIL WELLS Filed Nov. 27, 1931 5 Sheets-Sheet 4 3 C TR 1 I l I Fig. 8.

Inventor alt/ 7. eamarmm- Feb. 20, 1934. M. c. SEAMARK SNUBBING APPARATUS FOR OIL WELLS 1931 5 Sheets-Sheet 5 Filed NOV 27 Inventor 1: f7. jazz/mark.-

y 5 EL-M444 Patented Feb. 20,

UNITED STATES PATENT OFFICE Application November 2'7, 1931, Serial No. 577,575, and in Great Britain February 5, 1931 10 Claims.

This invention relates to so-called snubbing apparatus for oil wells.

The invention has among its objects to provide simple means by which snubbing-in may be conveniently and expeditiously performed, that is to say the forcing into the well of the drill pipe, casing or the like against the pressure within the well, the snubbing-out being permitted under the well pressure.

According to the invention a snubbing apparatus is provided comprising a pressure cylinder and ram device for snubbing-in or snub hing-out the drill pipe or casing in co-operation with upper and lower clamps independent of the drill operating gear. The pressure cylinder is carried in a frame by which the ram is supported in its reciprocation, and the frame is anchored at a position adjacent the well head and is supported upon the ground or upon a suit able base or foundation.

The invention also comprises the constructional features which are hereinafter described.

The invention is illustrated by way of example in the accompanying drawings, in which Figure 1 represents a diagram illustrating the operation of the apparatus.

Figure 2 is an end elevation showing the top clamp in position above the well casing to which the hydraulic cylinder is anchored.

Figure 3 is an under plan corresponding to Figure 2.

Figure i is a detail sectional view illustrating the construction of the tting by which the frame carrying the hydraulic cylinder is anchored to the well casing.

Figure 5 is an elevation of the hydraulic cylinder.

Figure 6 is a sectional elevation of the top clamp.

Figure '7 is a plan View corresponding to Figure 5, and

Figures 8 and 9 are elevation and plan respectively of the intermediate clamp.

Figure 10 is a detail longitudinal sectional elevation of the cylinder and ram device on a reduced scale.

In carrying the invention into effect the system of the fluid pressure medium employed may comprise a tank or reservoir 1, a pump 2, a pipe 3 extending from the tank to the inlet side of the pump, a pipe 4 extending from the outlet side of the pump 2 back to the tank 1, and a branch ipe 5 connected from the latter pipe to the closed end of an hydraulic cylinder 7' under control of a valve 6, independent valves '7, 8 being also provided to control the delivery of the fluid pressure medium from the pump 2 to the cylinder, and to control the discharge of the fluid pressure medium from the cylinder to the tank 1. In such a system water is advantageously employed. It will however be understood that any other convenient fluid pressure medium may be used, and that any convenient system for providing a fluid pressure medium under control for the operation of the cylinder and ram device according to practical requirements may be employed.

The apparatus according to the invention essentially involves the use of clamps a, b in the manner described to permit of the return of the top clamp a to its upper position for the purpose of drawing down further lengths of drill pipe h or the like and forcing it into the well, means being provided by which the slips or wedges c of the clamps are positively operated to engage the drill pipe or the like when the levers d which are mounted so as to beaccessible from the derrick floor. The top clamp a (Figures 1 and 3) is carried by a beam e centrally suspended by a lifting bale 6 while in position beneath the beam a clamp 2) (Figures 8 and 9) is carried upon a stationary supporting frame at such position that the drill pipe h or casing may be snubbedin in lengths for example of 20 feet, according to practical requirements. It will be understood that the upper end of the length of the drill pipe 72. or casing last inserted may be held in position by the stationary lower clamp b whereupon the top clamp a may be lifted into its upper position for engaging a further length of drill pipe or casing ready for the purpose of snubbing-in by the operation of the cylinder and ram device by which the beam and the clamp a are drawn down.

A blow off preventer of the construction described in the specification of a co-pending application Serial No. 483,290 dated 20th September 1930, may be mounted upon the well head flange Q The Well head flange may be carried at the upper end of the well casing g in position beneath the rotary table. In position immediately beneath the well head flange g a fitting i is mounted upon the upwardly protruding end of the casing g. The fitting i is of such form that it is adapted as a means for anchoring the cylinder and ram device or the frame by which it is carried. The fitting i is provided as a two part fitting, the main part i and the complementary part 2' The parts i and i are connected together by means of bolts 2' or the equivalent, and

have inclined recessed faces provided of a convenient number, such as six, at the internal cylindrical face of the parts of the fitting, for the reception of slips or wedges i of a corresponding form having serrated curvilinear front faces. The clips or wedges i are adapted to be inserted from above within the wedge-shaped cavities formed by the recessed faces provided on the fitting, so that thus the parts of the fitting may be tightly held beneath the well head casing. The parts i, i may meet in a plane passing through the centre line of the well casing. The main part i of the fitting is adapted for the reception of a shaft is that serves for carrying the chain sprockets k and for connecting to the well head casing the frame by which the cylinder and ram device is carried, in position transverse to the well casing and adjacent to it. For this purpose the part i may at each side be provided for the reception of the bolts 71 of a U-shape, the respective ends of the bolts being disposed parallel to each other and adapted to extend beyond the diametric face of that part of the fitting, through sets of holes provided at each side of the complementary part 2' of the fitting, nuts being adapted to be applied on the respective ends of the U-shaped bolts as a means for tightly securing the respective parts of the fitting together.

The main part i of the fitting that is adapted for the reception of the shaft 70 is provided in the position at the rear with a rearwardly extending pair of lugs 2' that are adapted to engage between them a protruding part 7' of the fitting in which the closed end of the hydraulic cylinder 7' is carried, and in which is integrally formed a passage for the fluid pressure medium communicating with the cylinder, this fitting 7' being provided with an upward branch :1' having an integral flange adapted for the reception of a valve or pipe connection, the fitting 7' being also provided in its main part at with faces at the top and bottom by which it may be secured in position between transversely disposed and parallel frame parts Z which are conveniently connected at the ends to brackets 2 that extend forwardly to carry the respective ends of the shaft k on which the sprocket wheels k are mounted, it being understood that the main part of the fitting 7' is provided for the reception within it of the end of the hydraulic cylinder 7', the cylinder being provided with an external thread at its end 7' or other means provided for securing a tight connection with the fitting. The brackets Z at their front ends extend downwardly to form a base Z by means of which they may be secured in position on the ground or upon a suitable foundation adjacent the well head and at each side thereof, to support the front end of the frame carrying the cylinder and ram device. The brackets Z are provided with laterally extending parts Z near their rear ends.

The outwardly extending brackets Z serve to carry at their ends longitudinal and parallel dis-- posed frame parts Z of a U-shaped section whose cavities are disposed inwardly, so that the longitudinal members Z may thus serve as run-ways for rollers m provided as hereinafter described for the support of the end of the ram m and the shaft m and sprockets m carried by it, while at the outer end the longitudinal members I may be supported upon timber or other supports Z It Will be understood that. the cylinder 9' and the ram m are advantageously disposed in alignment with the upwardly protruding end of the casing g and that the longitudinal frame members 1 are symmetrically disposed at each side of the centre as are also the brackets Z Z on which one end of the frame is supported upon the ground.

It will be understood that the cylinder 7' and ram m may advantageously be constructed of tubing such as that usually employed in well boring. Thus for example the cylinder 7 may be provided of a 13 inch casing, while similarly the ram m may be provided of a 10 inch casing. The inner end of the ram m may be provided with a cylindrical cap or cover m of an external diameter corresponding to that of the internal diameter of the cylinder 7', by which the inner end of the ram is closed. For this purpose the casing forming the ram m may be externally screwthreaded at its inner end for entry within the cylindrical cap m The outer end of the cylinder :i may be secured within an outer fitting m similar to that 7' in which the inner end of the cylinder is secured. The fitting 112 may be provided for the reception of packing m and a gland ring m to surround the ram m, and the outer end of the cylinder 7 may be screw-threaded externally for engagement within the fitting m This latter may be similarly provided with extensions or with oppositely disposed top and bottom faces, or it may be provided with outwardly extending flanges at the top, by means of which the fitting may be secured beneath a transversely disposed member Z of a channel-shaped transverse section, beneath the flat underface of which the fitting may thus be secured by means of bolts, and this transversely disposed member 1 may be supported by brackets Z at the respective ends carried upon the longitudinal members I.

The transversely disposed member I beneath which the outer end of the cylinder is thus carried serves at its respective ends for anchoring the ends of the chains n by means of which the outward movement of the ram imparts a downward movement to the beam carrying the top clamp a for the purpose of snubbing-in the drill pipe or the like.

The ram m at its outer end is provided with a fitting m whose outer part is adapted for the reception of two transversely disposed and parallel members m of symmetrical form and position one disposed over the other, the members m being advantageously formed of a channel section, the flanges of the lower member extending downwardly and the flanges of the upper member extending upwardly. These members m extend short of the positions at which the chains 12 are disposed, and the ends of the members m are adapted for the reception of outwardly extending brackets m for carrying the sprocket shaft m upon which the sprockets m are mounted in position between the respective brackets and the longitudinal frame members Z guide rollers m supported, and that the chains n extend respectively over the sprocket wheels m carried at the outer end of the ram m and at each side, the chains 11. respectively passing downwardly beneath the frame and beside the cylinder, passing thence forward beneath the sprocket wheels 761 ink) carried at the ends of the shaft is, the chains n thence passing upwardly and being connected to the lower ends of bolts n at the respective ends of the beam e by which the top clamp a is supported, it being understood that the respective chains n are set apart to such an extent as to clear the rotary table. Thus on the fluid pressure medium being admitted into the cylinder the ram is forced outward, thus applying tension upon the chains n and bringing down the beam e and the top clamp a by which the length of the drill pipe h or the like is forced into the well according to the extent of movement possible to the beam 6.

A helical spring y' having a number of open turns is advantageously applied upon the ram m, so that on it reaching the outer limit of its stroke it may come into contact with the cylindrical cap m carried upon the inner end of the ram, and thus an elastic resistance is imposed to further movement, whereby simple means are thus provided to give slack to the chains '11 and the snubbing clamp in preparation for taking another hold on the drill pipe h or the like.

The top clamp a may be carried in a central position within the beam e by which it is supported, and the beam may be made of metal in two longitudinal symmetrical parts e adapted upon their being brought into coincident relation to be secured together by means of bolts e to enclose centrally within them the slips or wedges c, by which the drill pipe h or the like may be clamped. The slips or wedges c are adapted to be lifted for securely engaging the drill pipe h or the like in order that it may be forced downwards into the well, or lowered to release the drill pipe h or the like to permit of the upward movement of the top clamp a and the beam e in preparation for the engagement of the drill pipe 71. or the like at a position above for snubbing in a further length thereof. For this purpose the central part of the beam e or of the cylindrical fitting c that may be centrally supported on the beame is provided with a concentric vertical bore through which the drill pipe h or the like may extend, and vertical and radial- 1y disposed recesses c providedat the inner face thereof, that are adapted for the reception from below of slips or wedges c, so formed and mounted in the recesses that when the slips or wedges c are moved upwardly the drill pipe h or the like may be engaged by them. The radial vertically disposed recesses are set at equal distances apart and may be adapted for the reception of wedges or slips 0 having opposite parallel lateral faces and curvilinear rear faces. The wedges or slips 0 may also be provided with reduced curvilinear inner faces, and adjacent those faces, angular faces c may be provided at each side. The angular faces 0 of adjacent slips or wedges 0 may be parallel and oppositely disposed and coincident circular recesses provided thereon a little distance beneath the upper ends of the slips or wedges 0 so that in that position helical springs 0 may be interposed between the slips or wedges c and be held at their ends in position within the coincident circular recesses. The upper part of the slips or wedges 0 may have their inner curvilinear face at c serrated and of a curvature corresponding to that of the drill pipe h or the like, while their outer faces may be slightly conical. The slips or wedges 0 may be at the lower part formed into an enlarged conical shape at c of the same taper or angle and they may terminate in an enlarged part c in position beneath the beam e, and an open annular slot 0 may be provided on the outer peripheral faces of the lower enlarged parts of the slips or wedges; while on the inner face at the lower end, the slips or wedges have a greater diameter than at the upper end. A lifting ring 0 is provided of a flat cross section and is adapted to engage within the open annular slots 0 whereby the slips or wedges are thus supported upon the lifting ring 0 and are thus adapted to be raised or lowered thereby. The lifting ring 0 is adapted for connection with the bifurcated end d of an operating lever d which may be carried by a downwardly and outwardly extending bracket e set at or near the centre part of the beam e, the bracket e being so disposed as to carry the operating lever cl to extend out angularly with respect to the beam e. At its outer end the lever 03 is provided with a fitting to which may be connected a rope accessible for operation from the derrick floor.

A packer ring 0 may be mounted beneath the beam on its under face in a position concentric with the clamp, and the packer ring 0 may be adapted for operation by an outwardly extending handle 0 so that it may be moved to engage or to clear the slips or wedges c and thus to keep the serrated inner faces of the slips or wedges c at their upper ends clear of the drill pipe h, or the like. The packer ring c may be of such form that it may be engaged by clip plates 012 for holding it in position, it being understood that the slips or wedges 0 may be positioned that they may rest upon a coupling of the drill pipe or the like in which position the serrations will be clear of the pipe.

The complementary clamp 19 may be provided of a similar construction to the top clamp, and is adapted to be secured to an auxiliary supporting frame below the rotary table, whereby the drill pipe or the like may be held in position when the top clamp is to be lifted. For this purpose instead of the cross beam support a cylindrical part b having oppositely disposed outwardly extending parts 22 may be provided that may be supported upon vertically disposed bolts 12 secured to the auxiliary support. The corresponding parts of the complementary clamp 22 are lettered corresponding to the lettering of the parts of the top clamp a.

It will be understood that the hydraulic cylinder and carrying frame mounted in the manner hereinbefore described do not require any prepared foundation but can be readily secured in the manner described to the upwardly protruding part of the well casing.

It will furthermore be understood that any other form and mounting of the slips or wedges of the clamps may be provided without departing from the invention as hereinbefore described.

I claim:

1. In snubbing apparatus for wells, means for operation comprising a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, and means at one end of the frame for anchoring the frame to the well head.

2. A snubbing apparatus for wells, comprising a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, means for anchoring the frame at a position adjacent the well head, movable and stationary clamps for engaging the lengths of tubing to be snubbed-in or out, and means for transmitting the movements of the ram to the movable clamp.

3. A snubbing apparatus for wells, compris ing a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, means for anchoring the frame at a position adjacent the well head, comprising a shaft supported transversely at one end of the frame, and a fitting adapted to carry the shaft and to be mounted on the well head casing, movable and stationary clamps for engaging the lengths of tubing to be snubbed-in or out, and means for transmitting the movements of the ram to the movable clamp.

i. A snubbing apparatus for wells, comprising a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, means for anchoring the frame at a position adjacent the well head, comprising a fitting mounted upon the well casing, movable and stationary clamps for engaging the lengths of tubing to be snubbedin or out, and means for transmitting the movements of the ram to the movable clamp.

5. A snubbing apparatus for wells, comprising a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, a front shaft supported transversely at one end of the frame, means by which the said front shaft is adapted to be connected to the well head casing, sprocket wheels at the respective ends of the said shaft, a transversely disposed shaft mounted at the outer end of the ram and sprocket wheels i mounted on the respective ends thereof, the said last-mentioned sprocket wheels being respective- 1y disposed in alignment with the sprocket wheels mounted upon the front shaft, means for guiding the shaft carried at the outer end of the ram, movable and stationary clamps for engaging the lengths of tubing to be snubbed-in or out, and means for transmitting the movements of the ram to the movable clamp, comprising a pair of flexible elements, the flexible elements being at one end fixedly held, a beam by which the movable clamp is carried, and means for the connec tion of the other ends of the flexible elements to the said beam.

6. A snubbing apparatus for wells, comprising a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, means for anchoring the frame at a position adjacent the well head, movable and stationary clamps for engaging the lengths of tubing to be snubbed-in or out, a crosshead at the outer end of the ram, means by which the crosshead is guided in the reciprocation of the ram and the sprocket wheels are carried upon the crosshead, flexible elements with which the said sprocket wheels engage and means for transmitting the movement of the said flexible elements to the movable clamp.

7. A snubbing apparatus for wells, comprising a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, a fitting fixedly connected to the frame at the front end, another fitting fixedly mounted at the upper end of the well head casing, a joint having a horizontal axis between the said f1- tings, movable and stationary clamps for engaging the lengths of tubing to be snubbed-in or out, and means for transmitting the movement of the ram to the movable clamp.

8. A snubbing apparatus for wells, comprising a pressure cylinder and ram device, means for cushioning the ram, comprising an enlarged part at the inner end of the ram and a helical spring adapted to engage the said enlarged part on the outward movement of the ram, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, means for anchoring the frame at a positionadjacent the well head, movable and stationary clamps for engaging the lengths of tubing to be snubbed-in or out and means for transmitting the movement of the ram to the movable clamp.

9. A snubbing apparatus for wells, comprising a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, means for anchoring the frame at a position adjacent the well head, movable and stationary clamps for engaging the lengths of tubing to be snubbedin or out, a rotatable packing ring for determining the position of the slips or wedges of the said clamps, and means for transmitting the movements of the rain to the movable clamp.

10. A snubbing apparatus for wells, comprising a pressure cylinder and ram device, a frame by which the cylinder and ram device is adapted to be supported lengthwise on the ground, means for anchoring the frame at a position adjacent the well head, sprocket wheels carried by the frame and disposed at the respective sides of the well head casing, movable and stationary clamps for engaging the lengths of tubing to be snubbed-in or out, the said clamps being disposed above and at each side of the well head casing, and means for transmitting the movements of the ram to the movable clamp, comprising flexible elements passing around the said sprocket wheels. LEWIS MERVYN CECIL SEAMARK. 

